Answer:
b = 363
Step-by-step explanation:
Sum of a geometric Progression is expressed as attached.
a = 3 = the first term
r = 3 = the common ratio
n = 5 = number of term
Sum of GP = a(r^n - 1)/ r-1
= 3(3^5 - 1)/ 3-1
= 3(234 - 1) / 2
= 3(242) / 2
= 726/2
= 363
